The present invention relates to a gas mixing apparatus used for uniformly mixing two kinds of gases, and is preferably applicable to a fuel gas combustion apparatus which generates a fuel mixture of fuel gas and air.
The Japanese Patent Application Laid-open No. 05-212259 (1993) discloses a static mixer including numerous rotary blades provided on the surfaces of two combined cones connected at their bottoms. This conventional static mixer provides numerous flow passages extending on the conical surfaces of two cones from one end (i.e. top of one cone) to the other end (i.e. top of the other cone), to produce a uniform mixture of a plurality of gases.
However, according to the above-described conventional gas mixing apparatus, the gases must be supplied to the pinnacle of one cone. To this end, the supply passage of the gases is narrowed (i.e. has a smaller diameter) in the vicinity of the gas inlet of the gas mixing apparatus. This arrangement increases the pressure loss.
In general, a blower or a comparable gas supplying device is provided to supply the gases to the gas mixing apparatus and is disposed in series with the gas mixing apparatus at the upstream side of this gas mixing apparatus. The mixing apparatus including the serially connected gas supplying means is long in the length in the gas flowing direction. When the gas mixing apparatus is assembled with a combustion apparatus or other apparatus, the overall size of the assembled apparatus body becomes larger.